This invention relates to rotary compressors, and more particularly it is concerned with a rotary compressor of the type suitable for use with an air conditioning system for an automotive vehicle for compressing a refrigerant.
In this type of rotary compressor, it has hitherto been usual practice to arrange the rotor with respect to the housing in such a manner that the end surfaces of the rotor and the inner end surfaces of the housing form therebetween a small gap (in the range between 0.02 and 0.03 mm). When this gap is too small, the end surfaces of the rotor would be brought into contact with the inner end surfaces of the housing due to thermal expansion during operation of the compressor, causing seizure to develop. Meanwhile, when the gap is too large, the compressor would have reduced efficiency because the refrigerant in the space on the high pressure side would pass through the gap to the space on the low pressure side. In view of this situation, various proposals have hitherto been made in this type of rotary compressor to enable the compressor to operate in satisfactory condition while keeping the aforementioned gap at a small value. However, all the proposals that have ever been made have been unable to attain the end of enabling a rotary compressor to operate with a high degree of efficiency with a small gap interposed between the end surfaces of the rotor and the inner end surfaces of the housing.